Q&A - Click a topic to see the question and answer

Question: I just bought a 2005 Dodge Viper convertible with 6,000 miles – after many Corvettes. What a car this is! I really like the exhaust sound, the rumble you get when you let off the gas to slow down. However, as you are aware, after about 4 seconds the fuel cut-off engages and the engine goes completely silent until around 1000 RPMs. Is there some way to disable the fuel cut-out, maybe an adjustment so the computer doesn’t realize the throttle is at idle (without triggering a fault code)? Thanks!

Answer: Funny you should bring this up. Dick Winkles and I always argue about the decel exhaust pop. I love it and he hates it. To change the deceleration fueling (which controls the pop) takes a reprogramming of the engine controller. Further complicating the situation is the effect it has on the emissions. That’s federal standard stuff so any changes must be recertified – expensive and time consuming. I’ll continue to beat on Dick!

Question: I own a 2004 Dodge Viper convertible and have a rear main oil seal leak that I can’t seem to solve. I have installed a new seal from Dodge and resealed the oil pan with a new gasket – also put Loctite® on all the pan bolts. I use Royal Purple SAE 10W-30 oil, just for your info. Do you have any suggestions on procedure or parts?

Answer: Sounds like you’ve done all the right stuff. The only thing I can think of is: Did you look at the crank flange surface that rides the seal? If there was a groove worn in it (even if slight) a new seal may not work. I know this would not be an easy thing to check now that you have the motor back together. I don’t know anything about the Royal Purple oil, but if it’s real slippery stuff, you might want to try going back to a factory oil fill just to see if that might help. It would be a relatively easy thing to do. Good luck.

Question: I have a question regarding my new 2001 Dodge Viper RT/10. The vehicle is red and has white stripes over the hood, top and trunk of car. Were factory stripes available on RT/10s in 2001? How can I find out if mine came with stripes from the factory?

Answer: After checking with SRT®, the consensus was factory stripes were not available for your car. It must have been done on the outside, later.

Question: I own a clean 1995 Viper RT/10 and I’m getting it ready for car shows. I’ve been trying to upgrade components under the hood with stainless steel braided lines and chrome or polished aluminum. I found a company that manufactures beauty fluid-reservoir covers to glue to brake and clutch reservoirs. They claim their kit is for 1996–2002 Vipers. Is there a difference between ’95 and ’96 Viper brake reservoirs? I’m not modifying any systems, just brightening things up.

Answer: There should be no difference between the brake reservoirs in ’95 and ’96 model-year Vipers—you should be all set.

Question: I have 170,000 miles on my 1996 GTS. I’m considering installing a 2008 Viper 8.4L V-10 engine in this vehicle. What extra parts and changeover procedures am I looking at beyond the long-block assembly, manifolds and the plumbing?

Answer: Boy, this would be a tough one to pull off. For starters, you’ll need a custom set of engine mounts. The new engine block has new mounting bosses. I believe the new accessory drive may not clear the old rainbow bar, so the bar will need a redo. As you pointed out, plumbing and exhaust will have to be custom fabricated, same with the airbox. Probably most difficult of all will be the electronic throttles. The entire engine control system is completely different and uses a different engine control module. There is zero backward compatibility. This would be a swap I’d stay away from. Now having said all that, when I retired at the beginning of ’08, there was talk of developing a kit to do the kind of swap you’re talking about—stay tuned, you never know.

Question: My questions are about driveline play/lash. My 2006 Dodge Viper SRT10® coupe, with 8,000 miles, seems to have excessive play when driving slowly on and off the throttle, so I was curious how much is normal and what can be adjusted or replaced to minimize it? What do you think of aftermarket neoprene engine and transmission mounts?

Answer: All Vipers have some driveline lash. It varies depending on clearances in the trans, u-joints and rear axle. Typically, the axle is a big contributor because of the diff and hypoid gearing. Unless it’s really severe, I wouldn’t be too concerned. Changing the backlash in the axle is a big deal, requiring professional expert knowledge and special tools, not to mention the cost (high). I recommend status quo.

Question: Why is rainwater an issue for Vipers and other collector cars? Even the new Hurst edition Viper that was featured in VIPER Magazine’s fall 2009 issue notes that the car left the show in a hurry, “... as a thunderstorm forced its early exit ...” Is it perhaps impurities in the rain? Not necessarily acid rain, but something otherwise damaging? In other words, what’s worse about a rain shower compared to a car wash in the driveway with tap water from a garden hose? I don’t drink either one these days but I’m having trouble understanding why a rainy day would be any worse than a gentle car wash?

Answer: There is no problem with your Viper’s paint/finish and the rain—rainwater poses no problem. When cleaning the exterior, use good quality car soap along with your tap water (softened if possible) and you should be fine. Regarding the Hurst Viper story, I was there at Carlisle when that car along with many others left before the storm. The weather report had severe thunderstorm warnings up with the threat of hail probable. That’s what got everyone moving, the sky looked awful. Shortly thereafter it poured.

Question: I have an extremely well-maintained 2000 GTS Steel Gray with silver stripes. Recently I decided to feature it in the World of Wheels Show, so I had it spruced up even more. I took the vehicle to a body shop to have my lower front bumper touched up and the rest of the car polished and buffed. The next morning I went to pick it up and the engine was knocking like hell. The shop owner had no idea what had happened—so he says! I took the car into a local Dodge dealer where they pulled the pan and found a broken piston, bent rod and maybe two more bad cylinders. Needless to say, everyone is in agreement that someone drove or over-revved the hell out of my engine. I contacted several companies and everyone agrees with this conclusion. I took the matter to my insurance company to battle for me, as I pay enough for the damn insurance. I informed them that the car is always well-maintained, never in the rain and I don’t race it—that type of damage can only be caused by abuse. Perhaps some kid at the body shop ruined the engine; as I don’t believe the owner who I gave the keys to would perform a buffing and polishing job himself. Do you feel this type of engine damage is most likely caused from abuse and/or negligence, and not a maintenance issue? Would an engine oil analysis shed light on how the engine was running long before the body shop arrival (as long as the engine oil was in the crankcase for a required mileage for the analysis test)? Please offer your insights on this subject. Thank you very much!

Answer: Certainly a grim situation to say the least. The damage you describe is typical of abuse. Since you mention that the car is well-maintained, I’ll assume the oil level was at the full mark, lending further evidence supporting abuse. The oil is probably contaminated with metallic debris, but if it were analyzed it might show that it was in basically good shape with its additive package intact—further evidence supporting your theory.

Question: I own a 1994 Viper and I am having trouble with it overheating. We have replaced the coolant and water in the radiator, and bled the system from the heater tap; however, the vehicle still throws water/coolant out of the expansion tank. Do you have any ideas as to what this problem may be? Any information would be great.

Answer: The first thing I’d try is refilling the system. You need to fill the system through the heater core but the engine has to be fully warmed up so the thermostat is open. Don’t forget to relieve the system pressure before you pull any hoses. If you still have trouble, the radiator may need to be pulled and professionally flushed.

Question: I own a 2008 Viper SRT10.® The vehicle may sit as long as 7 months without being operated. Do you recommend fogging the engine? What is the procedure to disable the engine from starting so that I may crank the engine over without it firing up? Do you have any winterization recommendations for long-term storage of my Viper?

Answer: Everybody has their favorite long term storage tips. Look for an article in an upcoming issue of VIPER Magazine. To your specific questions: fogging the motor is not required for storage up to a year. Make sure that if you do it you use oil specifically designated for fogging, anything else, and you are at risk because of possible contamination of the catalysts. If you want to crank the motor over without firing, pull the Auto Shut Down (ASD) relays (2). They are located in the Power Distribution Center (PDC) under the hood. The PDC is a black box and has the fuses in it. Some other tips would include a good wax job including the wheels, complete interior wipe down using leather wipes on the seats and some kind of tire treatment for the sidewalls. Store with a full tank of fuel including stabilizer and make sure the car was nice and hot when you put it away. Leave the windows part way down, unlatch the top and leave the trunk or hatch open slightly. Put the car in sleep mode (later models only) and use a battery tender (not a trickle charger). Oh yeah, a heated garage would help as well.

Question: In the Fall 2009 issue of VIPER Magazine, on page 17, there is an article about a 67 mm BBK throttle body for 2003–2006 Viper engines (62 mm being the factory size). Have you had any experience with this throttle body? Is the horsepower increase of “10 hp on average” plausible?

Answer: I have had no experience with the BBK product. As mentioned earlier, we never had time to rigorously test aftermarket parts. I discussed this product with my SRT® engine expert and he was skeptical about the horsepower increase.

Question: I own a 2005 Viper with 30,000 miles. I’ll be replacing the brake pads soon and I’m interested in your preference for brake pads (what brand?). Also, what pad material do you recommend for normal highway driving conditions versus severe track driving?

Answer: As I’ve said often, when I worked at SRT® we didn’t endorse aftermarket parts mostly because we didn’t have the time to thoroughly test them. For street driving, you can’t beat the Mopar® replacement pads. These are the same as the production parts that had all the benefits of SRT development testing. I know that the ACR development guys like the Mintex pads for track testing, so they might be worth a try if you’re spending a day at your favorite race track.

The guys say they run the Mintex on the front with production pads out back for optimum balance. Since more heat is generated with the race pads, consider upgrading your brake fluid to a higher temperature rating and bleed the system more often.

Question: My 2000 GTS will not engage gears. I was driving the car and took the transmission out of gear, then it would not go back in any gear. When the engine is not started the shifter can move in any gear position but when started will no longer engage. I can put the vehicle in gear to start it (with difficulty), but there is no clutch play and the car just leaps forward. I believe the problem is the clutch because before it warmed-up the clutch was a little soft/weak, but when warmed-up, felt strong. What do you think is causing the problem?

Answer: Definitely sounds like clutch trouble. A couple of easy things to check: first, look for wetness or drips at the bottom of the bellhousing. If you see this, the Concentric Slave Cylinder (CSC) is leaking and may need to be replaced. Before you tear it apart though, make sure the bleeder screw on the CSC is tight and not leaking. The not so obvious would be to make sure the clutch line is routed away from the exhaust system as far as possible and has an insulation sleeve on it. Of course, make sure the reservoir has fluid and don’t be surprised if the fluid looks dark—that’s normal. Finally, the system may need to be re-bled, but you need to ask yourself how it got that way in the first place because it’s not normal.

Question: I have a question regarding my 2008 Viper odometer. I recently took the vehicle to my Pennsylvania Inspection Station and repair garage—the odometer read 857 miles on delivery—when I picked up my Viper the odometer read 339,957 miles. The only other service they provided, other than vehicle inspection, was to add two key fobs. Any thoughts on what happened here

Answer: It’s difficult to say what might have happened without knowing exactly what the inspection station did during their checks. If they connected some kind of diagnostic equipment to the car it might have triggered some kind of reaction that led to the odometer problem. I would say it’s a long shot but with electronics, you never know.

Question: Recently I replaced the thermostat housing gasket in my 1995 RT/10. Normally the engine runs around 190°F. However, now it’s running at 220°F with the fan running continuously. I must have air in the system. What is the air-bleed procedure for this engine? Thanks for your help.

Answer: Before we talk about bleeding, you might want to check and make sure the T-stat is opening when it should. You can do this by putting it in a pot of water and heating it up until the stat opens up. Use a meat thermometer to track the temperature. Of course you have to tear the motor open to get it out so it’s a bit of a pain. The best way to bleed the early cars is to fill the system through the heater hose. Open up the heater valve and disconnect the incoming hose so you can fill the system through the heater core. The guys in our shop used to use a 5-gallon bucket sitting a few feet above the core. Start with a cold car. Don’t warm the car before you remove the hose. Let the engine idle so that the stat opens and keep filling until the air is purged. The disconnected hose can go back into the bucket so you don’t lose any coolant. I’m told that there are commercially available coolant system vacuum kits that may help with this situation. I’ve never used one but they should be available in most auto parts stores.

Question: I own a 1996 GTS and I’m considering installing a Mopar® Cat-BackTM exhaust system (P5007274). How much horsepower could the engine gain with this system? Please mention any benefits and drawbacks for this system. Do you recommend any other Mopar parts to increase horsepower?

Answer: Assuming your car is totally stock, the system should be good for 5 hp at the flywheel. The reason that the number is so small is that the stock system is very low restriction. Benefits will include better sound quality and perhaps reduced sill heat. On the down side, you may experience some exhaust drone on the highway. If it’s bothersome, try shifting up a gear. Some other parts you might consider are rocker arms with a different ratio, camshaft and ported heads. With these changes, the addition of the exhaust system would yield a 25-30 hp increase.

Question: I have 4,000 miles on my 2009 SRT10. I recently smoked the clutch on a steep incline. During normal driving I still smell a burning odor; however, the vehicle still shifts fine. Do I need a new clutch?

Answer: Probably not. The dual disc clutch is pretty robust. The smell will probably take a while to dissipate but should eventually go away. As long as the car launches okay and shifts fine, you should be good to go.

Question: After completing a hard run in my ’97 GTS, I noticed transmission fluid dripping from the transmission. The transmission fluid was changed recently. Is it possible the transmission was overfilled? If so, could this damage the transmission?

Answer: I’m assuming you had your car on a road course. You didn’t say what area the fluid was leaking from on the transmission. Most likely it’s coming from the vent which is on top of the trans. It’s possible it was overfilled, but it is also possible that the vent was dislodged during reinstallation. You need to take a look and see if the vent is still attached properly. Not easy to do, but you might be able to see it through the shifter opening.

Question: I’m the new owner of a 2006 Viper SRT10 coupe. The vehicle is black with silver stripe option M91. I need to know the Chrysler touch up paint part number for the M91 silver stripes as my dealer and local body shops are unable to find it. Also, what is the correct oil capacity for the 8.3L engine? My service manual shows 11 quarts; owner’s manual, 10 quarts; and 2006 brochure, 10.4 quarts—all with filter change.

Answer: The paint you are looking for is VA9. My paint expert suggested that you try to find a Dupont paint. This will give you the best match. The proper oil capacity for your car is 10.5 quarts with a filter change.

Question: I own a 2008 Viper SRT10® convertible with a set of Eibach springs installed. The vehicle has been lowered 1 inch. Typically, when I release the clutch quickly—at 2 to 3000 rpm rolling in first gear at around 20 mph—the vehicle wheel hops and I feel like I’m destroying the rear suspension. How can I correct this problem? The tire pressure in all four tires is at 30 psi.

Answer: Assuming nothing else has been changed on the car’s suspension, the hop issue may stem from the change in axle shaft angle because of lowering the car. Make sure that the fasteners are all retorqued properly—especially the shocks and control arms. If the Eibach spring rates are different than the stock springs, that may contribute significantly. Additionally, make sure the shocks are in good shape and show no signs of leakage.

Question: I have a 2005 convertible Viper that just turned 19,000 miles. The A/C works great around the city; however, on long drives and high speeds the vehicle gradually loses all blowing capacity coming from the vents (decrease in air velocity). The cab temperature eventually reaches a point were the windows need to be lowered. This occurs typically after about 20 to 30 minutes of driving. I adjust the fan level to max, but I can only feel the coolness at the vent, and I can hear the blower working, but there is no air flow coming from the vents. If I stop the car and let it sit for 15 to 30 minutes, it will work again, but as soon as I get back on the highway, it does it all over again. If the problem is with the vehicle’s vacuum system, how can this be corrected? Or is it something else? I would greatly appreciate your help!

Answer: This sounds like it might be a problem with the duct work—especially since the A/C works well around town. Look for a restriction when you are experiencing the reduced-flow. Look at the intake area near the base of the windshield near the intake box. Good luck.